Boat-propeller unit

Abstract

A boat-propeller unit comprises a carrier (4), a propeller-leg (5) and a sensor (13) which senses the angle of the propeller-leg relative to the carrier and which is intended for connection to an electrical indicating instrument mounted on the instrument panel of the boat. The sensor is of the kind which produces an output signal which varies as the distance of the sensor from an object and which is located centrally of a surface (11) on the propeller-leg, the distance of which from the sensor varies with changes in the angle of the propeller-leg relative to the carrier.

We claim: 
     
       1. In a boat-propeller unit comprising a carrier which can be mounted rigidly on a boat-transom, and a propeller-leg which is carried by the carrier and which can be adjusted to different angles relative to the carrier, by tilting the propeller-leg about a horizontal axis, and which can be swung about a steering axis which lies in a vertical plane, wherein means are provided for transmitting a signal contingent on the tilt-angle of the propeller-leg to an angle-indicating instrument; the improvement in which said means comprises a sensor (13) of the kind which produces an output signal which is dependent on the distance to a surface on an object, and an object (10) adjacent the sensor; the sensor and the surface on said object being so arranged in relation to one another on the carrier (4) and the propeller-leg (5) respectively that the distance therebetween changes in response to changes in the tile-angle on the propeller-leg thereby to change the sensor output signal. 
     
     
       2. A boat-propeller unit according to claim 1, wherein the sensor (13) is connected with a steering shaft (6) journalled on the carrier (4); and said object (10) comprises a body which is connected to the propeller-leg (5) and which has an extension perpendicular to the direction of the tilt-axis. 
     
     
       3. A boat-propeller unit according to claim 2, the sensor (13) is mounted in a central bore (12) in the steering shaft (6); and said object (10) has the form of a body which is so curved arcuately in front of the sensor that the distance between one end (15) of the sensor (13) and an opposing surface (11) on said body varies with varying tilt-angles of the propeller-leg. 
     
     
       4. A boat-propeller unit according to any one of claim 2 in which the steering shaft (6) is provided with a fork (7) which engages over a helmet (10) which is connected to the propeller-leg (5) and pivotally journalled on journal pins (9) on the legs of said fork, and wherein the sensor (13) is mounted in a bore (12) located in one end of the steering shaft (6) remote from the helmet (10); and when seen in longitudinal section the outer surface (11) of the helmet is curved in the plane of symmetry an in arc which is excentric with respect to the tilt-axis. 
     
     
       5. A boat-propeller unit according to claim 4, the sensor (13) is an inductive sensor; and the helmet (10) has a surface layer of magnetizable material at least in the region located opposite the end (15) of the sensor.